Substrate transfer apparatus

Abstract

In the substrate holder, while holding a periphery portion of a semiconductor wafer, some of protruding portions having a grass shape on a pad main body hide beneath the semiconductor wafer, and the others of the protruding portions are exposed outside the semiconductor wafer. Also, the protruding portions hiding beneath the semiconductor wafer contact a rear surface of the semiconductor wafer, and sink the semiconductor wafer to a suitable depth via gravity, thereby holding the semiconductor wafer mainly in a length direction. In addition, some of protruding portions exposed near the periphery portion of the semiconductor wafer contact a side surface of the semiconductor wafer, thereby holding the semiconductor wafer mainly in a width direction.

The invention claimed is: 
     
       1. A substrate transfer apparatus for holding and transferring a substrate, the apparatus comprising:
 a transfer body having a first top surface; 
 a plurality of substrate holders disposed on the first top surface so as to support a peripheral area of the substrate, 
 wherein at least one of the substrate holder comprises a pad main body having a second top surface, and a plurality of protruding portions upwardly extending from the second top surface, the protruding portions being elastically transformable in such a way that, when a substrate rests thereon, the substrate can be sunk down by the gravity thereof, and 
 wherein a portion of the protruding portions of each substrate holder contacts the peripheral area of the substrate, which is sunk down by the gravity of the substrate and a portion of a remaining portion of the protruding portions of each substrate holder is not elastically deformed and supports a side surface of the sunk-down substrate, thereby allowing the substrate to be held by the substrate holder when the substrate is misaligned or tilted, and preventing the substrate from escaping from the apparatus while the apparatus moves to transfer the substrate. 
 
     
     
       2. The substrate transfer apparatus of  claim 1 , wherein each of the protruding portions comprises a spring member and a cap portion covering a top portion of the spring member. 
     
     
       3. The substrate transfer apparatus of  claim 2 , wherein the cap portion is permitted to displace in a width direction. 
     
     
       4. The substrate transfer apparatus of  claim 1 , wherein each of the protruding portions is formed in a grass shape. 
     
     
       5. The substrate transfer apparatus of  claim 1 , wherein the plurality of protruding portions are arranged on a V-shaped line which has a peak facing a center point of the substrate. 
     
     
       6. The substrate transfer apparatus of  claim 1 , wherein heights of the plurality of protruding portions are equal to or smaller than a thickness of the substrate. 
     
     
       7. The substrate transfer apparatus of  claim 1 , wherein the transfer body has a recess portion that is formed on the first surface, and the pad main body is attached to an inside of the recess portion. 
     
     
       8. The substrate transfer apparatus of  claim 1 , wherein a depth in which the substrate sinks due to elastic displacement of the protruding portions is smaller than a thickness of the substrate. 
     
     
       9. The substrate transfer apparatus of  claim 1 , wherein the pad main body is configured to be detachable from the transfer body. 
     
     
       10. The substrate transfer apparatus of  claim 1 , wherein the plurality of substrate holders are arranged to only the peripheral area of the substrate. 
     
     
       11. The substrate transfer apparatus of  claim 1 , wherein the substrate transfer apparatus is used in a decompressed state. 
     
     
       12. The substrate transfer apparatus of  claim 1 , wherein the substrate transfer apparatus is provided for transferring the substrate under a high temperature process.